Somehow I only paid $37 for the PS3 version of Generations when I preordered it 6 months ago, with no Amazon fun bucks or anything like that involved. No idea how that happened.
I only played the demo of 2006 from back before it actually came out. The only thing I remember about it was how there were these rails you had to grind to get from platform to platform at one point. To start grinding, you jumped and then pressed jump again in midair next to the rail. The problem is, when you're NOT next to the rail, pressing jump in midair is the homing attack, which if there's no enemy around just makes you shoot forward. And the game was really finicky about you being in the right spot to start grinding. So most of my time with the demo was spent trying to grind these rails but ending up rocketing into a pit until I ran out of lives.
Sonic apologists insisted it was a "beta" and it would be "fixed" before release. Judging by the reaction to it when it came out, they were overly optimistic.